This U.S. non-provisional patent application claims priority under 35 U.S.C. § 119 of Korean Patent Application 2005-34144 filed on Apr. 25, 2005, the entire contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a self-running robot, and more particularly, to a pressing sensing technology of a self-running robot to sense pressing on the top of the self-running robot, and control driving of the self-running robot based on the sensed result so as to avoid obstacles or notify a user of the sensed result.
2. Description of Related Art
Robots were developed for industrial purposes and used as a part of a factory automation system. Further, the robots have been utilized to collect or gather information on behalf of humans in extreme environments humans cannot endure. Such a robot engineering field, while being recently used in a newest space development industry, has been continuously developed, and human-friendly home robots have been developed in recent years. A typical example of such human-friendly home robots is a cleaning robot.
The cleaning robot that is of a self-running type is an appliance which sucks dirt or debris, while self-running in a predetermined cleaning area such as a house or an office. Such a cleaning robot includes a moving unit including left and right wheel motors for moving the cleaning robot, a plurality of sensors for sensing obstacles so as to prevent the cleaning robot from striking obstacles in the cleaning area, and a microprocessor for controlling the overall device of the cleaning robot, together with constructions of a general vacuum cleaner to suck the dirt or debris.
Such a cleaning robot is configured to continuously clean a cleaning area while avoiding obstacles by changing its movement direction when obstacles are sensed through obstacle sensors installed in the robot during movement of the robot in the cleaning area.
However, although conventional cleaning robots can sense obstacles present in its running path within a certain sensible vertical range via obstacle sensors, it cannot sense an obstacle present at a level outside the sensible vertical range, in particular, a level higher than the sensible vertical range. For example, where there is an obstacle present at a level higher than the sensible vertical range of the cleaning robot, but lower than the level of the highest portion of the cleaning robot, the cleaning robot cannot sense this obstacle. In this case, if the cleaning robot runs continuously without sensing such an obstacle, the cleaning robot may become jammed between the floor and the obstacle, so that the top of the cleaning robot is pressed downwards by the obstacle. When the cleaning robot runs continuously without being stopped in this state, the pressing force applied to the top of the cleaning robot is increased, thereby causing the body of the cleaning robot to be damaged. Furthermore, the moving unit of the cleaning robot, in particular, the motor driving left and right wheels, may be severely damaged. In addition, the cleaning performance of the cleaning robot is degraded.